# Facade Lighting: Plan It Before the Facade Is Detailed

> Facade lighting design has to be settled before the facade is detailed, because the fittings need fixing points, cable routes, weather-tight penetrations, accessible driver locations and maintenance access that only the facade design can provide. Added later, it means drilled cladding, exposed cables and fittings nobody can reach, as well as glare and spill light that neighbours notice.

## The lighting is designed last, and the facade pays for it

On many buildings, facade lighting is decided after the facade is designed, fabricated
or even installed. A lighting scheme is drawn as a set of attractive night renders, and
the installer then has to find a way to fix the fittings, feed them and keep them
running.

That is the wrong order. **Facade lighting is a facade element, not an accessory.**
Every fitting needs a fixing point the cladding can carry, a cable that has to travel
somewhere, a penetration through the weather line, a driver that will one day fail, and
a person who can reach it. Decided late, those become drilled panels, surface conduits,
sealant-filled holes that leak, and fittings left dark because replacing them needs a
crane.

For a developer or owner the cost is both visible and recurring: a facade that looks
patched in daylight, leaks at new penetrations, and a lighting scheme that degrades as
fittings fail and are not replaced. The decision that avoids it costs very little, if it
is made at the facade design stage.

## What has to be decided before facade detailing

| Decision | If it is made late | Who should own it |
| --- | --- | --- |
| Fitting positions and fixing points | Brackets drilled into finished cladding; loads the panel was not checked for | Lighting designer with the facade engineer |
| Cable routes | Surface conduit across the facade, or cables through cavities not designed for them | Electrical designer with the facade engineer |
| Penetrations through the weather line | Sealant-only holes that leak | Facade engineer |
| Driver and power supply locations | Drivers buried behind fixed panels, or beyond permitted cable lengths | Lighting and electrical designers |
| Maintenance access | Fittings that need rope access or a crane for every fault | Facade access designer |
| IP rating and materials | Moisture ingress, corrosion and early failure | Electrical or lighting consultant |
| Controls and scheduling | Lights left on all night, or manual switching that is forgotten | Lighting and BMS designers |

## Cable routes, fixings and penetrations belong to the facade design

On a curtain wall, cables can sometimes run within mullions or behind spandrel panels,
and fittings can mount on brackets the facade engineer has designed for them. On a
rainscreen or cladding system, the cavity behind the panels may carry cables, but fire
breaks, drainage paths and ventilation openings in that cavity have to be respected.
Each of these is far easier to design in than to retrofit. The options differ by system,
which is why the lighting designer needs to work with the
[curtain wall](/services/facade-glazing/curtain-wall-systems) or cladding designer from
the start.

**Every penetration through the weather line is a potential leak.** A cable entry
designed into the facade, with a proper gasket or sleeve, is reliable. A hole drilled on
site and filled with sealant relies on that sealant for the life of the building.

Fittings on canopies, fins, louvres and other projecting elements raise the same
questions, and those elements are usually fabricated to order. Our page on
[architectural elements](/services/facade-glazing/architectural-elements) covers how
they are coordinated with the facade.

## Drivers, IP ratings and maintenance access

**Drivers.** LED drivers commonly fail before the light sources. A driver hidden behind a
fixed panel, high on the elevation, turns a small fault into an access operation. Drivers
should be reachable, protected from heat and water, and within the cable lengths the
fitting manufacturer allows, because long runs between driver and fitting can affect
performance.

**IP rating.** Outdoor fittings face driven rain, washing, dust and in some locations
salt. The [IP rating](/glossary/ip-rating) defined in **IEC 60529** states the tested
resistance to dust and water, and it holds only if the fitting is installed as tested,
with the right glands and seals. Uplights that face the sky collect water and debris,
which matters when choosing the rating and the drainage of the fitting. General safety
requirements for luminaires are set out in **IEC 60598-1**.

**Maintenance access.** Fittings should sit within reach of the facade's planned access
method, whether that is a building maintenance unit, a mobile platform from the ground,
or rope access. A fitting outside every access route will not be maintained.

**Batches and spares.** Colour and output vary between production batches, and fittings
age. Ordering spares from the same batch at the outset keeps replacements from standing
out on the elevation.

## Glare, spill light and neighbours

Facade lighting is meant to light the building, not the sky, the road or the flats
opposite. Light that misses the surface is wasted energy and can be a nuisance.

- **Aim at the surface.** Grazing light close to the facade wastes less than distant
  floodlighting.
- **Control the optics.** Shielding, louvres and narrow beams limit spill and upward
  light.
- **Hide the source.** A bright source visible from a neighbour's window or a driver's
  line of sight is glare, even if the facade looks right.
- **Switch it off.** A curfew, after which the scheme dims or turns off, reduces both
  nuisance and energy use.

Obtrusive light from outdoor installations is addressed in **EN 12464-2**, and the
International Commission on Illumination publishes guidance on limiting obtrusive light
by environmental zone. Any local authority conditions on illuminated facades or signage
should be checked by the project team.

## Control, scheduling and energy

A facade scheme without controls tends to run all night, every night. Astronomical time
switches, curfew settings and integration with the building management system let the
lighting follow sunset and a set switch-off time automatically. Colour-changing schemes
need a control protocol, and a decision on who will programme and maintain the scenes.

Lighting and control provisions for commercial buildings, including exterior lighting,
are set out in **ECBC 2017**. How those provisions apply to a specific building is for
the lighting or energy consultant to establish. A night mock-up on a small area of the
facade, alongside any [facade mock-up testing](/glossary/facade-mock-up-testing), is the
most reliable way to judge glare, colour and brightness before the full order.

## Who holds the scheme together

Facade lighting sits between trades. The lighting designer chooses fittings and effects,
the facade engineer controls fixings and penetrations, the electrical designer feeds and
protects the circuits, and the access designer decides what can be reached. When each
assumes another has it covered, the gaps appear on site: a bracket with no backing, a
cable with no route, a driver with no home.

The practical answer is a single coordination drawing for each elevation, showing every
fitting, its fixing, its cable path, its driver and its access route, signed off by each
discipline before facade shop drawings are approved. It is a modest piece of work at the
right moment and a very expensive one after the panels are made. A design-and-build
contractor should treat the lighting as part of the facade package, not as a separate
order placed at the end.

## Common mistakes

- **Lighting designed from renders after the facade is fixed.** Brackets are drilled
  into finished panels.
- **Cable routes left to site.** Surface conduit appears across the elevation.
- **Drivers placed where nobody can reach them.** One failure darkens a section for
  months.
- **One IP rating for every fitting.** Uplights and sheltered fittings face different
  exposures.
- **No curfew or schedule.** The building lights the sky all night.
- **No spares from the original batch.** Replacements do not match.

## What to ask before the facade is detailed

- Where will each fitting fix, and has the facade engineer allowed for it?
- How will cables reach each fitting, and where do they cross the weather line?
- Where are the drivers, and how will someone replace one?
- Which access method reaches every fitting?
- What IP rating is specified for each location, and why?
- How will spill light and glare towards neighbours and roads be controlled?
- What switches the lighting on and off, and who maintains the programme?

## Standards referenced

Degrees of protection for enclosures in **IEC 60529**; general requirements and tests for
luminaires in **IEC 60598-1**; outdoor lighting and obtrusive light in **EN 12464-2**;
and lighting and control provisions, including exterior lighting, in **ECBC 2017**.
Fitting selection, IP ratings, fixing design, electrical design and any authority
conditions for a specific building must be established by the project's lighting,
electrical and facade engineers.

## Frequently asked questions

### When should facade lighting be designed?

Before the facade's fixing, bracket and joint details are frozen, ideally alongside the facade design itself. Fittings need fixing points the facade engineer has allowed for, cable routes behind or within the cladding, sealed penetrations through the weather line, and access for maintenance. Each of those is cheap to include in the facade design and expensive to retrofit.

### What IP rating do facade light fittings need?

It depends on the exact position and exposure: driven rain, washing, dust, whether the fitting faces up and can collect water, and whether it is in a coastal or polluted atmosphere. The rating must hold as installed, with correct glands and seals. The project's electrical or lighting consultant should set the rating for each location rather than applying one figure to the whole facade.

### Where should LED drivers for facade lighting go?

Somewhere they can be reached for replacement without a crane or rope access, kept within the cable length the manufacturer allows, and protected from heat and water. Drivers often fail before the LEDs do, so a driver hidden behind a fixed panel high on the facade turns a small fault into an access operation. Locate them during facade design.

### How do we stop facade lighting disturbing neighbours?

Aim light at the surface rather than past it, use optics and shielding that limit spill and upward light, avoid bright sources visible from neighbouring windows and roads, and dim or switch off after a set time. EN 12464-2 and international guidance on obtrusive light describe how this is assessed. Local authority conditions, where they exist, should be checked by the project team.

### Does facade lighting fall under the energy code?

ECBC 2017 addresses lighting and controls for commercial buildings, including exterior lighting. Whether and how its provisions apply to a particular building, and what power and control requirements follow, should be established by the project's lighting or energy consultant. Good practice is the same either way: efficient fittings, light only where it is needed, and automatic scheduling.

### Can facade lighting be added to an existing building?

Yes, but expect compromises. Fixing points must be engineered into existing cladding or glazing, every penetration has to be sealed, cables need a route that does not look like an afterthought, and access for maintenance may be limited to what the existing facade allows. A night mock-up on a small area is worth doing before committing.

## Sources

- [IEC 60529](https://webstore.iec.ch/en/) — Degrees of protection provided by enclosures (IP code)
- [IEC 60598-1](https://webstore.iec.ch/en/) — Luminaires - general requirements and tests
- [EN 12464-2](https://standards.cencenelec.eu/ords/f?p=CEN:105) — Light and lighting - lighting of work places - outdoor work places, including obtrusive light
- [ECBC 2017](https://beeindia.gov.in/) — Lighting and controls, including exterior lighting

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Source: https://hagerstone.com/blog/facade-lighting-plan-before-the-facade-is-fixed